This invention relates in general to telephone network interface devices and in particular to such a device having a half-ringer test circuit that can be readily disconnected.
A network interface device (xe2x80x9cNIDxe2x80x9d) may be utilized for buildings that have a number of communications lines. The NID provides a demarcation point between the provider lines and the subscriber lines. The NID also allows the subscriber lines to be readily disconnected from the provider lines for test purposes. Typically, for each separate line there will be a jack having a receptacle for an RJ-11 plug. The provider lines are electrically connected to two contacts of the jack. The plug is located on the end of a flexible lead that connects to the subscriber terminals. Inserting the plug into the receptacle places the subscriber terminals in continuity with the provider wires. Removing the plug isolates the subscriber terminals from the provider line for test purposes.
Additionally, some providers prefer to have a half-ringer test circuit included in the NID for testing purposes. In the past, the half-ringer test circuit has been electrically wired in parallel, but physically wired in series between the provider wires and the subscriber terminals within the NID. In particular, the half-ringer test circuit has typically been physically wired in series between the provider lines and two of the contacts of the RJ-11 jack.
The half-ringer test circuit is principally used for testing voice telephone communication lines. It is not compatible with high-speed digital data transmission over telephone lines. Accordingly, if a subscriber is converting a conventional telephone line to a higher speed data line, such as a xe2x80x9cDSLxe2x80x9d line, the half-ringer must first be disconnected. This presents a problem if the subscriber line is one of many other lines within a building, all leading to the same NID. Removing a half-ringer involved opening the provider side of the NID, cutting four wires and splicing the two provider wires to the two subscriber wires. Subsequently, if that data line was being converted back to a conventional telephone line having a half-ringer, the only way to add the half-ringer back would be to open the provider side of the NID again, cut the two provider wires and reconnect the two provider lines and the two subscriber lines to the half ringer so that the half-ringer is once again physically wired in series between the two provider lines and the subscriber terminals. This practice is not craft-friendly and presents maintenance difficulties.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate one or several embodiments of the invention, and, together with the description, serve to explain the principles of the invention.
The NID in this invention has a housing with a conventional jack mounted in the housing for each communications line. The jack has a subscriber receptacle having first and second pairs of contacts. A pair of provider wires are electrically connected to the first pair of contacts in the subscriber receptacle. A pair of subscriber terminals are mounted in the housing and adapted to be connected to a pair of subscriber wires. A subscriber plug mates with the subscriber receptacle and is connected to a flexible lead. The lead has a first pair of wires that connect the first pair of contacts in the subscriber receptacle to the subscriber terminals. The lead has a second pair of wires that selectively connect the second pair of contacts in the subscriber receptacle to the subscriber terminals.
A test circuit is mounted in the housing and connected by a pair of test wires to the second pair of contacts in the subscriber receptacle. Thus, the second pair of wires of the lead connect to the test circuit when the subscriber plug is plugged into the subscriber receptacle. The second pair of wires of the lead have free ends that may be selectively connected to the subscriber terminals to connect the test circuit. Conversely, the free ends may be selectively disconnected from the subscriber terminals to disconnect the test circuit.